@ahsat’s wheels are creaking. It seems to be coming from the spoke nipples. it’s definitely the wheels, you can simulate it with the wheel out and flexing it.
They’re DT P1750 straight pull wheels on her road bike. Wheels are true and tension seems ok by feel (no meter). The wheels about a year old, but light use. The rims are taped ready for tubeless so I’ve ran a small amount of tri-flo oil from the spoke side in to the nipples, but they still creak. Could they need tensioning? Any other ideas?